Selecting system for elevators



May 17, 1960 s. A. HORNUNG Erm.

sELEcTING SYSTEM FOR ELEvAToRs Filed oct. 14, 1958 2,936,858 SELECTIN G SYSTEM FOR ELEVATORS Stephen Anthony Hornung, New York, and Angelo Fusco, Brooklyn, N.Y., assignors to Otis Elevator Company, New York, N .Y., a corporationof New Jersey Application October 14, 1958, SerialNo. 767,126 20 Claims. (Cl. 187-29) The invention relates to elevator systems and' particularly to apparatus for selecting the order in which cars are to depart from aV predetermined landing.

The invention is particularly applicable to dispatching systems it is advantageous to dispatch the cars from a dispatch landing on a non-sequence basiswithout regard to the order in which they have previously departed from that landing. When the cars are dispatched o n a nonsequence basis, the cars are selected for dispatching in the order in which, they arrive at the dispatch landing, except where there is an accumulation of cars` at the dispatch landing from which the selection may be, made, in which case selection is usually made on a rotational basis. Selection of the next car takes place incident to the. dispatching of the then selected car from the dispatch landing when one or ymore other cars is at the dispatch landing at the time the dispatching takes place. lf no other cars are there, selection takes place asv soon as another car arrives atA the dispatch landing. With such an arrangement, selection is made before dispatching takes place, thus allowing time for the selected car to be loaded. Selection is indicated to waiting passengers, usually by lighting the hall lantern` or a sign for the particular car which is selected, advising them which car will be the next to leave. Also in systems in which the cars are attendant controlled, selection is indicated to the car attendant to advise him when tok start loading his car. The invention is particularly directed to non-sequence dispatching systems.

The object of the invention is to improve the operation of an elevator system in its selection of the elevator cars for starting from a given landing.

One feature of the invention is to select in advance of its arrival at the dispatch landing the next car to be dispatched, under conditions where no car is available at the dispatch landing for such selection.

* United States Patent() Another feature of the invention is also to select in advance of its arrival at the dispatch landing the second car to be dispatched, under conditions where no car is available at the dispatch landing for such selection.

The selection of the next car to be dispatched is indi- -cated to waiting passengers at the dispatch landing as soon as the selection takes place. Thus the advance indication of selection where the, selection takes place prior to arrivai of the selected car at the dispatch landing enables the waiting passengers to get into position to board the selected car before it arrives. This decreases the loading time with the result that the dispatching interval may be shortened7 thus expediting elevator service.

The selection of the second car to be dispatched is aiso indicated to waiting passengers at the dispatch landing. Thus any excess of waiting passengers whoy are unable to board the selected car, may move into position to board the next car, as soon as it becomes the next selected car and arrives at the dispatch landing.

The selection of the next car to be dispatched in advance of its arrival at the dispatch landing may be used alone or in conjunction with the selection of the second car to be dispatched. When used alone, there may be, at the time the dispatch of the selected car is initiated, under conditions where no other car is at the dispatch landing',` two or more down traveling cars within` an advance ICC selection zone. Under such conditions, the car which will be the first to reach the dispatch landing is selected as the next to be dispatched. When used in conjunction with the selection of the second car to be dispatched, upon the dispatch of the selected car, the selection ot the next car is transferred to the car selected as the second car to be dispatched. Here again there may be, at the time the selection is transferred, no car at the dispatch landing to be selected as the new second car to be dispatched but two or more cars other than the new next selected car may be traveling down within an advance selection zone. Under such conditions, the nearest ot such cars tothe dispatch landing is selected as the second car to be dispatched.

The invention is particularly applicable to installations in which the elevator cars operate express in a lower zone in a building and will be described as applied tothe erpress elevators of such an installation. When applied to such an installation, the advance selection zone extends from a point in the express zone at which down traveling cars entering the express zone will have attained full speed.

Other features and advantages of the invention will be seen from the above and from the following description and appended claims.

The invention will be described for convenience as applied to dispatching cars from a lower dispatch landing, which may be the lobby of the building and which will hereinafter be termed the main landing. Also, it will be described as applied to a four car bank of express elevators. As the cars may also serve ay basement, basement operation is included. Although the invention is applicable to various forms of elevator dispatch and control systems, it will be described with reference to the dispatch and controi system disclosed in the Glaser and Hornung Patent No. 2,589,242. In such a system, when operating with attendants, the cars are manually started by the attendants in the cars upon receipt of dispatch signals and, when operating without attendants, the cars are dispatched by automatically starting the cars. While the invention is applicable to dispatching and control systems with attendant operation, it is particularly applicable to such systems in which the cars. are operated without attendants.

In the drawings:

Figure l is a simplified schematic wiring diagram of a portion of the elevator dispatching and control system, which includes circuits embodying the invention; and

Figure ls is a key sheet for Figure l showing the electromagnetic switches in spindle form.

The circuits are shown inA across-the-line form, the relationship of the coils and contacts being seen from Figure ls where the coils and contacts are in horizontal alignment with the corresponding coils and contacts in the wiring diagram. To facilitate and Simplify the disclosure, only a portion of the dispatching and control circuits is shown and those shown relate to selection of the cars for dispatching from the main landing.

The electromagnetic switches employed in the system illustrated are designatedY as follows:

DN-Down direction switch FR--Flicker switch LCS- Lowest call switch UP-Up direction switch VB-Availability switch VUR--Up selecting switch WBX-Up dispatch holding switch XCS-Car in service switch YB-Advance availability switch ZB--Car selected switch ZBX-Auxiliary car selected switch In the wiring diagram, these letters are applied to the coils of the switches and, with reference numerals appended thereto, are applied to the contacts of the switches. The contacts of the switches are shown for switch deenergized condition. Only the contacts of switches DN, UP, WBX and XCS are illustrated, the circuits for their coils being shown in the aforementioned Glaser and Hornung patent. Also only the contacts of switch LCS are illustrated, the circuit for the coil being as shown in the Glaser and Lustri Patent No. 2,682,318, moditied as will be explained later. Switch ZB has both an operating coil and a holding coil. Except for switch VUR, these switches are individual to the elevators, that is, each elevator has one of each of them. Differentiation Iwill be made between the different elevators by appending to the reference characters employed to designate lthese switches and various other elements of the system individual to the elevators, lower case letters a, b, c and d, indicative of the diiierent elevators Ifor which they are provided.

Switch VUR is a rotary stepping switch utilized in the selection of the cars. It is provided with three banks, each bank comprising a series of stationary contacts, one for leach car, and a movable brush adapted to engage the stationary contacts in succession. One of these banks represented by stationary contacts VURCI and brush VURB1 control the selection of the cars. Another represented by stationaiy contacts VURCZ and brush VURBZ control the circuits for the coils of car selected switches ZB. The third bank represented Iby stationary contacts VURC3 and brush VURB3 control the circuits for the coils of flicker switches FR. The brushes of the rotary stepping switch are rotated in step by step movement by the operating coil. Successive deenergizations of the operating coil to cause stepping operations are effected by contacts VURI.

Each car is provided with a switch Z which is actuated to closed position by car movement when the car traveling in the down direction arrives at a predetermined distance below the top of the express zone. This distance is such that the car will be traveling at `full speed at this point. This insures that a down car that has operated its switch Z will not be overtaken by a following car as might happen if these switches were positioned say at the top of the express zone and for example one car entered the zone at full speed following a car which entered the zone at a slow speed due to a stop |at the next landing above. Each switch remains closed until actuated to open position by the car for which it is provided, as the car returns to that point in its upward movement.

Each car is also provided with a switch N which is actuated by car movement to closed position, as the car leaves the main landing to go to the basement and is actuated to open position, as the car returns to the main landing from the basement.

Each car is provided with a selector machine, as described in the aforementioned Glaser and Hornung patent. Each selector machine has a stationary contact M for the main landing which is engaged by the movable brush B on the synchronous panel, incident to the car arriving at the main landing. Preferably switches Z and N for each car are operated by the synchronous panel of the selector machine for that car.

Each car is also provided with a lamp LP1 for indicating to waiting passengers at the main landing when lighted that that car is selected for dispatching. This lamp may be the up hall lantern for the car at the main landing. When the system is also arranged to select not only the next car ,to be dispatched but also the second car to be dispatched, each car is also provided with another lamp LPZ to indicate to the waiting passengers at the main landing when lighted that that car will be the second car to be dispatched. In such case, the lamp LP1 may be arranged to illuminate a THIS CAR UP sign and lamp LP2 may be arranged to illuminate a SECOND CAR UP sign.

W+ and W- designate direct current supply lines for the system. Resistors are designated generally as R and capacitors are designated generally as C. T are electron tubes, one for each elevator, in the circuits controlled by switches Z. These tubes may be thyratrons such as type RCAZOSO, each having control grid, anode, cathode and suppressor grid electrodes, the latter two being connected together. The control grid of each tube is connected through a resistor-capacitor network comprising, for ltube Ta for example, grid resistors RSa, R611, R7a and grid capacitor Cla to supply line W- and to its anode circuit. The cathodes of all tubes are connected together and to supply line W| through current limiting resistors R2 and R3. These cathodes are also connected to supply line W- by means of a resistor-capacitor network comprising resistors R4 and R8 and capacitor C2.

For a volt supply and for the type of electronic tube specified, the following ohmic values of resistors and capacities of condensers in the electronic circuits have been found satisfactory:

Resistors:

R2 -ohms-- 40,000 R3 do 15,000 R4 d0 1,500 R5 megohms 3.6 R6 ohms-- 220,000 R7 megohms-- 2.4 R8 ohrns 250 Condensers: I Microfarads C1 250 C2 l0 The invention will first be described as arranged for lselecting both the next car to be dispatched and the second car to be dispatched. Assume that all cars are in service so that contacts XCSI, XCS2 and XCS3 for each car are engaged. Assume also that all cars are at the main landing so that selector brush B for each car is in engagement with its corresponding selector stationary contact M. Thus upon the application of voltage to supply lines W-i and W-, a circuit is completed for the coil of the availability switch VBa for car a, the circuit extending from line W-lthrough XCSla, WBXla, LCSla, Ba, Ma, ZBXla and VBa to line W-. Similar circuits are cornpleted for the coils of availability switches VBb and VBd for cars b to d, respectively. Thus, all the VB switches are operated and contacts VBla, VBlb, VBlc and VBld are engaged. Assuming further that all cars are set for upward travel, the up direction switches UP for cars a to d are operated and remain operated until the cars for which these switches are provided reverse their direction of travel. Thus contacts UPla, UPlb, UPlc and UPld are engaged and a circuit is completed from line W-lthrough the parallel circuits extending through VBI and UP1 for each elevator, resistor R3, capacitor C2 and resistor R8 to line W-, charging capacitor C2 in the common cathode return circuit of tubes Ta to Td to establish a predetermined grid bias, for purposes to be explained later. Also contacts VB3 of each VB switch are separated. Assuming that brush VURBI is in engagement with stationary contact VURCla for car a at this time, no operation of the up selecting switch VUR takes place due to the fact that the circuit for its coil is open at contacts VB3a. Thus car a is selected to be the first to start upward from the main landing. Had brush VURBI been in engagement with'a contact for some other car, say contact VURClb for car b, instead, no operation of the up selecting switch VUR would have taken place because the circuit for its coil would have been open at contacts VB3b. Under such conditions, car b would be the car selected as the first car to leave.

Also, contacts VB4 and VBS of each VB switch are engaged. Thus with brush VURBI in engagement with contact VURCla, selecting car a as the first to leave the :for the coil of icker switch FRa, which releases.

ranlanding.. brush VUR-B2 -is in' engagement with sta tionary' contact VURCZa for car a so that a circuit is completed; for the operatingA coil of car selected switch ZBa for car a; 'Ihis circuitextends from line W+ through VB'4'qf', ZBa, VURCZa, VURBZ, ZBXSa, ZBXSb, ZBXSc kandv ZBX3d to line W-. Also brush VURB3 is in engagement with stationary contact VURC3a so that valcircuit for the coil of llicker switch FRa for car a is complete, this circuit extending from line W-I- through FRa, R9a, R10a, VBVSa, VURC3a and VURB3 to line W-. The purpose of the tiicker switches will be explained' later.

Car' selected switch ZBa operates to engage contacts ZB2a,. completing a circuit for itsho'lding coil and for the coil. oftheA auxiliary car selected switchZBXafor car a, the: circuit extending from line W-I- through XCSla, W-BXIa, LCS'la, Ba, Ma, ZBZ'a, Rla and ZBa to line W4- andy through MSa and ZBXa in parallel with ZBa-t SwitchZBz also separates contact'sZB4a-in thecircuit'for lamp LPZa and engages contacts ZB3ato complete a circuit' for lamp LPl'a. Lamp LPla illuminates the THIS CAR UP sign for .car av to indicate that this car will be the first dispatched. i

Auxiliary car selected switch ZBXa operates to separate contacts ZBXla, interrupting the circuit for the coil of switch` VBa. Switchl ZBXa also separates contacts ZBXSa, breaking the circuit for the operating coil of switch ZBa. Switch ZBa is maintained operated by its holding coil when contacts ZBX3a separate. Switch VBa releasesto separate contacts VBSa, breaking the circuit Thus while, under the assumption made, a circuit is completed for the coil of switch FRa, this circuit is immediately .brokenandis thus of no consequence'.

Switch'VBa, upon releasing, also engages contacts VB3a Switch VUR notches its brushes Coil separated, theoperatingcoil of switch ZBb for car b can- 4not` be energized. However, a circuit is completed for `the-coil of flicker switch'FRb for car b, the circuit being 'like that traced for the coil of switch FRa and extending 'through contact' VURC3b and brush VURB3. -liick'er switch is alternately' operatedl and released by the This :action of its short circuiting contacts FRZb,.being delayed iinr releasing by the discharge of condenser C3b into its ico'il'. Thus, its contacts FRlb` alternately engage and separate to cause flickering of lamp LP2b which illuminates the SECOND CAR UP sign for car b. Thus waiting'passengers are advised that car b will be the next to be dispatched after car a.

Next assume that car a is dispatched. Incident to this dispatching operation, the up dispatch holding switch WBXa is operated and remainsoperated until car a leaves the main landing. Switch WBXa, upon operation, separates its contacts WBXla, interrupting the circuit for the holding coil of switch ZBa and the coil of switch ZBXa ,for car a. Switch ZBa releases to separate contacts ZB3a, which interrupts the circuit for lamp LPla, thereby extinguishing the THiS CAR UP sign for car a. Switch ZBXav releases to engage contacts ZBXSa, completing a circuit by way of contact VURCZb and brush VURBZ for the operating coil of switch ZBb for car b. Switch ZBb operates to engage contacts ZB2b, completing a circuit for its holding coil and for the coil of switch ZBXb for car b, the circuit being like that above traced for the holding" coil of switch ZBa and the coil of switch ZBXa.

' Switch ZBb also engages contacts ZBSb, completing a circuit for lamp LPlb for car b to illuminate the msegses CAR UP` sign positioned above the entranceway to car b, and separates contacts ZB4b to interrupt the circuit of lamp LPZb, thereby extinguishing the SECOND CAR UP sign for car b. Thus waiting passengers are advised that car b will be the next car dispatched.

Switch ZBXb operates to separate contacts ZBXSb, in.- terrupting the circuit for the operating coil of switch ZBb for car b. However, switch ZBb is maintained in operated condition by its holding coil. Switch ZBXb also separates contacts ZBXlb, interrupting the circuit for the coil of switch VBI; for car b. Switch VBb releases to separate contacts VBSb, interrupting the circuit for the coil of switch FRb for car b. Switch VBb also separates contacts VBZb and engages contacts VB3b to complete a circuit -through contacts VBZc for the coil of switch VUR. Switch VUR notches to its next position, moving its brushes VURBI, VURBZ and VURB3 into engagement with stationary contacts VURClc, VURCZc and VURCSc, respectively, for car c, where they remainy due to separated contacts VB3c. Contacts ZBXSb, which are now separated, prevent completion of the circuit for the operating coil of switch ZBc for car c at this time. The engagement of brush VURB3 with contact VURC3 completes a circuit -through contacts VBSc for the coil of switch FRC for car c. Switch FRC operates as above described to cause the ickered lighting of lamp LPZc which illuminates the SECOND CAR UP sign for car c, advising the waiting passengers that car c will be the next to be dispatched after car b.

In a manner similar to that already described, incident to the dispatching of car b, car c is selected as next to be dispatched and car d is selected as the second to be dispatched. Then incident to the dispatching of car c, car d is selected las next to be dispatched.

.It is to be noted that as each car is selected for dispatching, the availability switch for that car releases, separating its contacts. Therefore, as car d is selected and contacts VBld separate, resistor R2 is inserted in series with condenser C2now in a charged state, as previously set forth. Resistor R2 is of suicient ohmic value to reduce the potential applied to condenser C2 to a value which causes this condenser to discharge partially through resistor R4. This makes the cathodes of tubes Tato Td less positive with respect to their respective grids, decreasing the grid bias applied to these tubes to value which will permit their ionization, as will be explained.

Assume now that car d is dispatched so that all cars are away from the main landing. Assume next that car b traveling in the down direction arrives at the point in the express zone where it closes switch Zb. Since car b is traveling downward, contacts DNZb of the down direction switch for car b are engaged. Thus switch Zb cornpletes the anode-cathode circuit of tube Tb through the coil of switch YBb. This circuit is from line W| through XCS3b, Zb, DNZb, LCSZb, ZBX2b, YBb, Tb and R4 to line W and through C2 and R8 in parallel with R4 to line W-. Due to the charge on condenser C2, the voltage thus applied to this circuit is insuticient to cause ionization of tube Tb. Switch Zb also completes a circuit for grid condenser Clb from line W+ through XCSb, Zb, DNZb, LCSZb, ZBXzb, R5b, and Clb to line W-. Condenser Clb charges quickly to a value to raise the grid Ito cathode potential of tube Tb suihciently to cause conduction of the tube to take place. Thus the delay in causing conduction of the tube is only momentary.

As conduction takes place, switch YBb for car b operates to engage contacts YBlb, completing a circuit for the coil of switch VBb for car b, this circuit extending from line W-lthrough XCSlb, WBXlb, YBlb, ZBXlb and VBb to line W-. Switch VBb upon operation, er1- gages contacts VBZb, VB4b and separates contacts VBSb. Since, as has been previously stated, car d was the last car dispatched, -a circuit is completed for the coil of switch VUR through contacts VB2b and VB3d, contactVURC1d and brush VURBI. Switch VUR notches its brushes VURBI, VURBZ and VURB3 into engagement with stationary contacts VURClb, VURCZb and VURCSb, respectively for car b where they remain, due to separated contacts VB3b. A circuit is thus completed by way of contacts VB4b, contact VURCZb and brush VURB2 for the operating coil of switch ZBb for car b. Switch ZBb, upon operation, engages contacts ZBZb, completing a circuit for its holding coil and for the coil of switch ZBXb, Switch ZBb also engages contacts ZB3b completing a circuit for lamp LPlb illuminating the THIS CAR UP sign for car b, thereby advising waiting passengers in advance of the arrival of car b at the main landing that car b is selected as the next car to be dispatched from that landing.

Switch ZBXb, upon operation, separates contacts ZBXlb, interrupting the circuit for the coil of switch VBb. Switch ZBXb also separates contacts ZBXSb, break- 'ing the circuit for the operating coil of switch ZBb. How- Next assume that car a traveling downward actuates switch Za to closed position, completing the anodecathode circuit of tube Ta through the coil of switch 'YBa and also completing a circuit for condenser Cla,

which charges to a value to cause tube Ta to conduct. As a result switch YBa operates, engaging contacts YBla to complete a circuit for the coil of switch VBa. Switch VBa upon operation, engages contacts VBZa, VB4a and VBSa and separates contacts VB3a. Thus, a circuit is completed by way of contacts VBZa and VB3b for the coil of switch VUR. Switch VUR notches bmshes VURBI, VURBZ and VURB3 into engagement with contacts VURCla, VURCZa and VURCScz, respectively, where they remain due to separated contacts VB3a. Contacts ZBX3b, which are now separated, prevent completion of the circuit for the operating coil of switch ZBa. However, the circuit for the coil of flicker switch FRrz is completed through contacts VBSa. Switch FRa operates to cause ilickered lighting of lamp LPZa, which illuminates the SECOND CAR UP sign for car a, thereby advising waiting passengers in advance of the arrvial of car a at the main landing that it Will be the next car tube Td and causing grid condenser Cld to begin charging. Since tube Ta is conducting, the voltage drop across resistor R4, which resistor is common to the cathodes of tubes Ta to Td, drives the cathode of tube Td sutil- "ciently positive with respect to its grid to maintain this tube in nonconducting condition.

Similarly, as car c, traveling downward, operates switch Zc to closed position, applying voltage to the anodecathode circuit of tube Tc and causing grid condenser Clc to begin charging, tube Tc is maintained in nonconducting condition by the voltage drop across resistor R4 in the common cathode circuit.

Next assume that car b, which is selected as the next car to be dispatched, arrives at the main landing, becomes set for up travel and then is dispatched in a manner similar to that previously described in connection with car a. As car b is dispatched, contacts ZBXSIJ engage, completing a circuit through brush VURBZ and eration, engages contacts ZBla, completing a circuit for its holding coil and the coil of switch ZBXa, thereby transferring the selection of the next car to be dispatched to car a, the nearest down traveling car. In doing so, switch ZBa extinguishes the SECOND CAR UP sign for car a and illuminates its THIS CAR UP sign, as has been previously described, to advise waiting passengers of the status of car a in advance of its arrival at the main landing.

Switch ZBXa, upon operation, separates contacts ZBXZa, interrupting the anode-cathode circuit of tube Ta which ceases to conduct, causing condenser C2 to start discharging through resistor R4. Since condenser Cld started charging before condenser Clc, the grid of tube Td is presently at a more positive value with respect to its cathode than is the grid of tube Tc with regard to its cathode. Therefore, as condenser C2 discharges, the grid to cathode potential of tube Td is the first to attain a value sufcient to cause this tube to conduct and energize the coil of switch YBd for car d. At the same time, as tube Td conducts, tube Tc is biased to a nonconducting condition by the voltage drop across resistor R4, as has been previously explained.

Switch YBd, upon operation, engages contacts YBld, completing a circuit for the coil of switch VBd for car d. As has been previously described in connection with car a, car d, the lowermost of the remaining down traveling cars, is thus selected in advance of its arrival at the main landing as the car second to be dispatched and flickers its SECOND CAR UP sign to indicate its status to waiting passengers at the main landing.

It is to be noted that the value of capacity, previously given, of condensers Cla to Cld is so selected that these condensers do not approximate their full charge in the time required for a car to travel the entire length of the express portion of its hoistway. This insures that, as condenser C2 begins to discharge with two or more cars traveling downward in the express zone, each of which has closed its switch Z, as has been described, the potential diiference between the grid and cathode of the tube for the lowermost car is always the first to attain the breakdown voltage of that tube, so that the lowermost of two or more down traveling cars is the one selected for dispatching.

Assume now that cars a and d arrive at the main landing in that sequence and become set for up travel. VAs car d becomes set for up travel, contacts DN2d separate, interrupting the current flowing through tube Td and the coil of switch YBd. However, as contacts YB1d separate, switch VBd for car d is maintained operated through selector brush Bd, which is now in engagement with selector contact Md. As tube Td ceases to conduct, condenser C2 starts to discharge through resistor R4. At the same time, contacts UPld engage and together with engaged contacts VBld short circuit resistor R2, thereby applying sufficient voltage of a positive polarity to condenser C2 to maintain tube Tc in nonconducting condition.

Next assume that car a is dispatched and selection as the next car to be dispatched is transferred to car d, in a manner similar to that described previously for car a. VIncident to this transfer of selection, switch ZBXd operates, separating contacts ZBXld to interrupt the circuit for the coil of switch VBd. Switch VBd releases to separate contacts VBld, inserting resistor R2 in series with condenser C2 which discharges through resistor R4 suiciently to cause tube Tc to conduct, thereby selecting car 'c in advance of its arrival at the main landing, as the car to be dispatched after car d, as has been previously described for car d.

It thus can be seen that in the absence of a car available for dispatching at the main landing, the lowest car traveling toward the main landing in a given zone is selected as the next car to be dispatched and the next nearestr caris selected as ythe second to be dispatched.

'Ifhel status of these two cars is indicated to waiting passengers in advance of the cars arriving at the main landang, thereby expediting the loading of the cars. A third car traveling toward or arriving at the main landing is prevented from interfering with this selection. As the iirst car selected 'arrives at the main landing and is dispatched, selection as the next car to be dispatched is transrferred to the car selected as the second car to be dispatched and the lowermost of the remaining down traveling cars with actuated switches Z is selected as the second car to be dispatched. This advance selection of the second car to be dispatched is especially valuable during periods of heavy up traic, such as the up peak period in the morning.

In some installations it may be desirable to select only the next car to be dispatched. This operation may be provided in the system illustrated, In such case, in the absence of a car available for selection at the main landing, only the next car to be dispatched is selected in advance of its arrival and such selection is indicated by illuminating the THIS CAR UPI sign for the selected car. Selection of all other cars is prevented until the dispatching of this tirst selected car is initiated. This may be accomplished by opening manual switches MS (a to d), thereby disabling the auxiliary car selected switch ZBX for each car. In this manner, once the tube T for aI particular car conducts, incident to the selectionot'y that car as the next to be dispatched, it remains conducting, preventing all other tubes from conducting, until the selected car arrives at the main landing and becomes set for up travel. As the selected car becomes set for up travel, its associated contacts DN2r separate, interrupting the anode-cathode circuit of the conducting tube. However, switch VB of the selected car, operated in response to the operation of switch YB for that car, is maintained operated by the engagement of brush B for that car with its M contact. Thus contactsVBl for that car are engaged and since contacts UPl for that car are now engaged, resistor R2 is short circuited. This raises the potential of condenser C2 and thus the potential of the cathodes of all tubes preventing other cars yfrom being selected for dispatching until the dispatching ofthe particular car is initiated. Therefore, the lowermost car is selected in advance of its arrival as the next car `to be dispatched, and a second car is not selected until the selected car arrives at the main landing andi. its dispatch is initiated. In this arrangement, waiting ,passengers are advised as to which car will be the next car dispatched in advance of its arrival at the main landing. v

As has been set forth previously, the operation under conditions where basement service is provided has been included. Involved in this operation is lowest call switch LCS for each car. The control circuits for the coil of switch LCS for each car, shown in the Figure 3 of the aforementioned Glaser and Lusti Patent No. 2,682,318, are modified by the provision of additional (normally closed) contacts on switch ZB for that car connected in series with the coil. With this modiiication, when selection of a car as next to be dispatched takes place, either in advance of arrival of the car at the main landing or While the car is there, switch ZB for that car operates, separating its additional contacts to prevent the energization. of the coil of switch LCS in response to a basement car call for that car, a down landing call for the main landing or a basement landing call. Thus the assignment of such a selected car to basement service is prevented. When selection of a car as next to be dispatched has not taken place, so that the additional contacts ofswitch ZB for that car are not separated, the registration of a basement car call for a down traveling car causes operation of switch LCS and if such selection has-not. been made by the time the car approaches the main ylanding and causes engagement of contacts HLR3 of-theaforementioned Glaser and Lusti patent for that car,A a'A registered down landing call for Vthe main landing or a registered landing call for the basement causes operation of. switch LCS for that car. Such LCS switch, when thus operated, causes separation of its contacts LCSZ to prevent conduction of tube T and thus switch YB for that car. Thus, the advance selection of that car as next to be dispatched is prevented and the car is assigned to basement service. Switch LCS also separates its contacts LCS1 for that car under such conditions, thereby preventing the selection of that car as next to be dispatched in response to the engagement of brush B` for that car with its contact M incident to the car arriving at the main landing.

In order to provide adequate basement service where the arrangement for selecting the second car to be dispatched is being employed, it is preferred to allow such second selected car to respond to a call for service to the basement. This is accomplished by switch LCS for that car, which switch is responsive to calls for basement service when switch ZB for that car is not operated. Thus, upon operation of switch LCS for the second selected car in response to a call for basement service, its contacts LCS and LCS2 separate, causing such second selected car to lose that selection, enabling it to respond to the basement call. Selection as the second selected car may be transferred to another car approaching the main landing, as will be explained.

In either case, if a car is assigned to basement service in response to a down landing call at the main landing, if no one enters the car and presses the basement car button within a certain time interval after the stop at the l car and enabling it to be selected as next to be dispatched, as explainedtin the aforementioned Glaser and Lusti patent.

A car leaving the-main landing for the basement moves the switch N for that car to closed position, short circuiting resistor R2 through engaged contacts XCSZ to increase the grid bias of the tubes T, thereby preventing advance selection, either as next or second to be dispatched, of any car traveling downward toward the main landing, and not already selected, until it arrives at a predetermined distance from the main landing, say two feet for certain installations. At this point the down traveling car engages its selector brush B with its contact M, causing operation of its switch VB so that the car is rendered available for selection.

A car traveling to the main landing from the basement landing is rendered available for selection before it arrives at the main landing. As such car arrives at a certain distance from the main landing, say six feet for certain installations, its brush B engages its contact M, causing its switch VB to operate. InV the absence of a car selected as the next to be dispatched (or as the second car to be dispatched where switches MS are closed), and assuming no unselected down traveling car hasY already engaged its brush B with its contact M, the car traveling from the basement, by means of its brush B and contact M operating its switch VB, becomes selected, either as the next car, or as the second car to be dispatched in case the next car has already been selected, before the basement car actually arrives at the main landing andso advises waiting passengers at the main landing. If this car is so selected as the second carto be dispatched, orV if it is so selected as the next car, where switches MS are open, its switch VB, upon operation, remains operated, as has Vbeen previously described, and engages its contacts VBI, which through engaged contacts UPl` for that car, short circuit resistor R2 to prevent the advance selection of any other down traveling car after the car arriving from the basement upon arrival at the main landing moves its switch N to open position. Therefore, this arrangement givespreference for selection to a basement` car.- However; if a'downtraveling unselected car arrives.

near enough to the main landing to cause its brush B to engage its contact M before the brush B of the car traveling from the basement engages its contacts M, the down traveling car, instead of the basement car, will be selected, as its switch VB is operated.

In certain installations which include basement service, especially those having a relatively long express zone, the switches Z may be positioned a considerable distance below the top of the express Zone, so that a car can only be selected in advance of its arrival, by means of its switch Z and its associated tube T, when it is near enough to the main landing that it will arrive at the main landing before a car, responding to a call for that basement, returns to the main landing. In such a case, as a car responding to a call for the basement leaves the main landing, moving the switch N for that responding car to closed position, it will minimize the possibility of advance selection of any down traveling car which cannot arrive at the main landing before the responding car returns to the main landing. With the switches Z positioned at this point, an unselected down car which is already below the position for operating its switch Z when selection is to be made will, in all probability, engage its brush B with its contact M before the basement car and thus become the selected car, as has been previously described.

As changes can be made in the above described construction and many apparently different embodiments of this invention can be made without departing from the scope thereof, it is intended that all matter contained in the above description or shown on the accompanying drawing be interpreted as illustrative only and not in a limiting sense.

What is claimed is:

l. An elevator system of a plurality of elevator cars serving a plurality of landings comprising, means for each car for starting that car, and means operable incident to the starting of a selected car from a given one of said landings for selecting the next car to be started from such landing, said selecting means including means operable under conditions where no other car is at such landing but more than one car is traveling toward such landing and is within a predetermined selection Zone extending a certain distance from such landing at such time, for selecting the nearest one of such cars tosuch landing, regardless of their order of previous departure from such landing.

2. A selecting and dispatching system for a plurality of elevator cars operating from a dispatching landing, said system comprising, means for dispatching the cars in succession from said dispatching landing in the order of their selection, measuring apparatus responsive to the movements of the cars while traveling toward but removed from said dispatching landing and within a certain selection Zone proximate to said dispatching landing for producing a signal indicative of which one of said cars will iirst arrive at said dispatching landing, and selecting means responsive to said signal under conditions where the next proceding selected car has been dispatched by said dispatching means and no other car is at said dispatching landing for selecting as next to be dispatched the car so indicated by said measuring apparatus.

3. In an elevator installation in which a plurality of cars serve several iioor landings of a building from a dispatching landing and in which visual indicating means for each of said cars are provided at said dispatching landing, means for dispatching selected cars from said dispatching landing, selecting means actuatable for selecting the car next to be dispatched from said dispatching landing by said dispatching means, measuring apparatus responsive to the movements of the cars while still remote from but traveling toward said dispatching landing, said measuring apparatus being adapted under conditions where the next preceding selected car has been dispatched by said dispatching means and no other car is at said dispatching landing for causing an indication by said visual indicating means of which one of the remote cars will first arrive at said dispatching landing and causing said selecting means to select that car while preventing the indication of the arrival and the selection of any other of such traveling cars.

4. A dispatching system for a plurality of elevator cars operating from a dispatch landing comprising, means for dispatching the cars in succession from the dispatch landing in the order of their selection, and means operable incident to the dispatching of a selected car from said dispatch landing under conditions where no other car is at said dispatch landing for selecting a car traveling toward said dispatch landing and within a certain distance thereof, said last named means including means operable under conditions where more than one car traveling toward said dispatch landing is within said certain distance thereof at such time, for selecting the nearest one of such cars to said dispatch landing, regardless of their order of previous departure from said dispatch landing.

5. A dispatching system for a plurality of elevator cars operating from a dispatch landing comprising; means for dispatching the cars in succession from the dispatch landing in the order of their selection; and means operable incident to the dispatching of a selected car from said dispatch landing for selecting the next car to be dispatched from said dispatch landing, said selecting means including means operable under conditions where one other car is at said dispatch landing at such time for selecting such other car, regardless of the order of previous departure of the cars from said dispatch landing, and further including means operable under conditions where no other car is at said dispatch landing but more than one car is traveling toward said dispatch landing and is within a certain distance thereof at such time, for selecting prior to its arrival at said dispatch landing the nearest one of such cars to said dispatch landing, regardless of their order of previous departure from said dispatch landing.

6. A dispatching system for a plurality of elevator cars operating from a dispatch landing comprising; means for dispatching the cars in succession from the dispatch landing in the order of their selection; and means operable incident to the dispatching of a selected car from said dispatch landing for selecting the next car to be dispatched from said dispatch landing, said selecting means including means operable under conditions Where one other car is at said dispatch landing at such time, for selecting such other car, regardless of the order of previous departure of the cars from said dispatch landing, and further including means operable under conditions where no other car is at said dispatch landing but more than one car is traveling at normal speed toward said dispatch landing and is within a certain distance thereof at such time, for selecting prior to its arrival at said dispatch landing the nearest one of such cars to said dispatch landing, regardless of their order of previous departure from said dispatch landing.

7. A dispatching system for a plurality of elevator cars operating from a dispatch landing comprising; means for dispatching the cars in succession from the dispatch landing in the order of their selection; and means operable incident to the dispatching of a selected car from said dispatch landing for selecting the next car to be dispatched from said dispatch landing, said selecting means including means operable under conditions where one car is at said dispatch. landing at such time for selecting such other car, regardless of the order of previous departure of the cars from said dispatch landing, and further including means operable under conditions where no otherA car is at said dispatch landing but at least one car is traveling toward said dispatch landing and is within a certain distance thereof at such time, for selecting prior to its arrival at said dispatch landing the nearest ear to said dispatch` landing, regardless of the order. 'of its previous departure from said dispatch landing.

8,. A dispatching system for a plurality of elevator cars operating from a dispatch landing comprising, means for dispatching .the cars in succession from the dispatch landing inthe order of their selection; a plurality of signals at said dispatch landing, one for; each car, for indicating to waiting passengers at the dispatch landing which car is the next to be dispatched from said dispatch landing; means operable` incident to fthe dispatching of a selected car from said dispatch landing for selecting the next car to be dispatched from said dispatch landing, said selecting means including means operable under conditions where one other car is at said dispatch landing at such time forjselecting such other car, regardless of the order of previous departure of the cars from said dispatch landing, and further including means operable under conditionswhere no other car is ait said rdispatch landing but more than one car is traveling toward said dispatch landing and is Within a certain distance thereof at such time, for selecting prior to its arrival at said dispatch landing the nearest one of such cars to said dispatch landing, regardless of their order of previous departure from said dispatch landing; and means responsive Yto the selection of a car for dispatching for causing the giving of said signal for that car, whereby waiting passengers are advised which car is so selected to expedite loading time.

9. A`dispatching system for a plurality of elevator cars operating from a dispatch landing comprising; means for dispatching the cars in succession from the dispatch landing in the order of their selection; irst selecting means operable incident to the dispatching of a selected car from said dispatch landing for selecting the next car to be dispatched from said dispatch landing, said iirst selecting means including means operable under conditions where. one other car is at said dispatch landing at such time, for selecting such other car as next to be dispatched, regardless of the order of previous departure of the cars from said dispatch landing, and further including means operable under conditions Where no other car is at said dispatch landing but. more than one car is traveling at normal speed toward said dispatch landing and is within a certain distance thereof at such time, for selecting prior to its arrival at said dispatch landing the nearest one of such cars to said dispatch landing as next to be dispatched, regardless of their order of previous departure from said dispatch landing; and second selecting means operable incident to the dispatching of a selected car from said dispatch landing for selecting the second car to be dispatched from said dispatch landing, said second selecting means including means operable under conditions where one other unselected car is at said dispatch landing atsuch time, for selecting such other unselected car as second to be dispatched, regardless ofthe order of previous departure of the cars from said dispatch landing, and further including means operable under conditions where no other unselected car is at said dispatch landing but more than one unselected car isl traveling at normal speed toward said dispatch landing and is within a certain distance thereof at such time, Yfor selecting prior to its arrival at said dispatch landing the nearest one of such unselected cars to said dispatch `landing as secondV to be dispatched, regardless of their order of previous departure from said dispatch landing.

10. A dispatching system for a plurality of elevator cars operating from a dispatch landing comprising; means for dispatching the cars in succession from the dispatch landing in the order of their selection; rst selecting means operable incident to the dispatching of a selected car from said dispatch landing for selecting the next car to be dispatched from said dispatch landing, said rst selecting` means including means operable under conditions where one V other car is at said dispatch landing at suchtime, for selecting such other car as next t be dispatched, regardless of the order of previous departure of the cars from said dispatch landing, and further including means operable under conditions Where no other car is at said dispatch landing but more than one car is traveling at normal speed toward said dispatch landing and is within a certain distance thereof at such time, for selecting prior to its arrival at said dispatch landing the nearest one of such cars to said dispatch landing as next to be dispatched, regardless of their order of previous departure from said dispatch landing; second selecting means operable incident to the dispatching of la selected car from said dispatch landing for selecting the second car to be dispatched from said dispatch landing, said second selecting means including means operable under conditions where one other unselected car is at said dispatch landing at such time, for selecting such other unselected car as second to be dispatched, regardlessk of the order of previous departure of the cars from said dispatch landing, and further including means operable under conditions where no other unselected car is at said dispatch landing but more than one unselected car is traveling at normal speed toward said dispatch landing and is within a certain distance thereof at such time, for selecting prior to its arrival at said dispatch landing the nearest one of such unselected cars to said dispatch landing as second to be dispatched, regardless oftheir order of previous departure from said dispatch landing; and transfer means also operable incident to the dispatching of a selected car from said dispatch landing for causing said irst selecting means to transfer the selection as the next car to be dispatched to a. car selected as second to be dispatched under conditions where a car has been so selected by said second selecting means.

11. A dispatching system for a plurality of elevator cars operating from a dispatch landing comprising; means for dispatching the cars in succession from the dispatch landing in the order of their selection; means operable incident to the dispatching of a selected car from said dispatch landing for selecting the next and second cars to be dispatched from said dispatching landing, said selecting means including means operable under conditions where at least two other unselected cars are at said dispatch landing at such time, for selecting two of such other unselected cars as next and second to be dispatched, regardless of the order of previous departure of the cars from said dispatch landing, and further including means operable under conditions where only one other unselected car is at said dispatch landing at such time but more than one unselected car is traveling at normal speed toward said dispatch landing and is within a certain distance thereof at said time, for selecting said one other car as next to be dispatched and for seiecting prior to its arrival at said dispatch landing the nearest one of such unselected cars to said dispatch landing as second to be dispatched, regardless of their order of previous departure from said dispatch landing.

l2. A dispatching system for a plurality of elevator cars operating from a dispatch landing comprising; means for dispatching the cars in succession from the dispatch landing in the order of their selection; means operable incident to the dispatching of a selected car from said dispatch landing for selecting the next and second cars to be dispatched from said dispatch landing, said selecting means including means operable under conditions where at least two other unselected cars are at said dispatch landing at such time, for selecting two of such other unselected cars as next and second to be dispatched, regardless of the order of previous departure of the cars from said dispatch landing, and also including means operable under conditions where only one other unselected car is at said dispatch landing at such time but more than one unselected car is traveling at normal speed toward said dispatch landing and is within a certain assenso distance thereof at said time, for selecting said one other car as next to be dispatched and for selecting prior to its arrival at said dispatch landing the nearest one of such unselected cars to said dispatch landing as second to be dispatched, regardless of their order of previous departure from said dispatch landing, and further including means operable under conditions where no other vunselected car is at said dispatch landing but at least two unselected cars are traveling at normal speed toward said dispatch landing and are within a certain distance thereof at such time, for selecting the nearest of such unselected cars to said dispatch landing `as the next to be dispatched and the next nearest to said dispatch landing as the second to be dispatched, prior to their arrival at said dispatch landing7 regardless of their order of previous departure from said dispatch landing.

13. A dispatching system for a plurality of elevator cars operating from a dispatch landing comprising; means for dispatching the cars in succession from the dispatch landing in the order of their selection; first selecting means operable incident to the dispatching of a selected car from said dispatch landing for selecting the next car to be dispatched from said dispatch landing, said first electing means including means operable under conditions where one other car is at said dispatch landing at such time, for selecting such other car as next to be dispatched, regardless of the order of previous departure of the cars from said dispatch landing, and further including means operable under conditions where no othet car is at said dispatch landing but more than one car is traveling at normal speed toward said dispatch landing and is Within a certain distance thereof at such time, for selecting prior to its arrival at said dispatch landing the nearest one of such cars to said dispatch landing as next to be dispatched, regardless of their order of previous departure from said dispatch landing; and second selecting means operable incident to dispatching of a selected car from the said dispatch landing and under conditions where one other car is already selected as next to be dispatched by said first selecting means, for selecting the second car to be dispatched from said dispatch landing, said second selecting means including means operable under conditions where a second other car is at said dispatch landing at such time, said means selecting said second other car as second to be dispatched, regardless of the order of previous departure of the cars from said dispatch landing, and further including means operable under conditions where no second other car is at said dispatch landing but more than one unselected car is traveling at normal speed toward said dispatch landing and within a certain distance thereof at such time, for selecting prior to its arrival at said dispatch landing the nearest one of such unselected cars to said dispatch landing as second to be dispatched, regardless of their order of previous departure from said dispatch landing.

14. A device for indicating which one of a plurality of elevator cars in an elevator installation will be the rst to arrive at a predetermined oor landing, said device comprising, means responsive to the relative positions of said cars as they travel toward said predetermined landing for determining which of said traveling cars will first arrive at said predetermined landing, and means selectively responsive to said first named means for indicating in advance of its arrival which car is so determined to arrive first while excluding any advance indication of the arrival of said other cars at said predetermined landing.

l5. in an elevator installation in which a plurality of cars serves several floor landings of a building and in which there is provided mechanism adapted for dispatching said cars from a predetermined one of said landings, a device for selecting said cars for dispatching and for indicating which one of said cars will be next dispatched from that dispatch landing, said device comprising first means responsive to the relative positions of said cars as said cars travel toward said dispatch landing for determining which of said cars so traveling will first arrive at said dispatch landing, second means responsive to the presence of of said cars at said dispatch landing selecting means operatively responsive to operation of said second means for selecting said cars present at said dispatch landing for dispatching by said dispatch mechanism in accordance with a predetermined sequence, said selecting means in the absence of any of said cars at said dispatch landing also being responsive to operation of said first means for selecting the nearest car to said dispatch landing as next to be dispatched, and indicating means responsive to actuation of said selecting means for indicating which of said cars so selected will be next dispatched.

16. ln an elevator system adapted for dispatching a plurality of elevator cars from a preselected floor landing, a device for selecting and indicating the sequence in which said car will be dispatched from said landing, said device comprising, car position determining means for determining the relative position of each of said cars with respect to said landing, first selecting means operatively responsive to said position determining means for selecting in a predetermined sequence for dispatching any of said cars positioned at said landing, second selecting means also operatively responsive to said position determining means for selecting for dispatching the car traveling toward said landing which is nearest to said landing, said second selecting means being prevented by said first selecting means from so selecting said nearest car until said first selecting means ceases to select cars for dispatching, and indicating means responsive to said first and second selecting means for indicating at said landing which car has been selected for dispatching.

17. In an elevator system adapted for dispatching a plurality of elevator cars from a preselected iioor landing, a device for selecting for dispatching the nearest car traveling toward said landing and indicating that selection at said landing in advance of the arrival of that car thereat, said device comprising, first position determining means responsive to the positions of said cars for determining the position of each of said cars relative to each other while said cars are traveling toward said landing, first selecting means selectively responsive to said position determining means for selecting only the car nearest to said landing, dispatch selecting means responsive to said selection of said nearest car by said first selecting means for selecting that car in advance of its arrival at said landing as the car to be dispatch from said landing, said dispatch selecting means when so operated preventing selection of any other car for dispatching until said selected car is dispatched, second position determining means responsive to the position of any of said cars at said landing for disabling said dispatch selecting means from selecting for dispatching any of said cars traveling toward said landing, and indicating means positioned at said landing for indicating said selection of said nearest car, said indicating means being actuated by said dispatch selecting means substantially simultaneously with said selection for dispatching for indicating in the absence of any of said cars at said landing which car traveling toward said landing is selected for dispatching in advance of its arrival at said landing.

18. In combination with an elevator control system adapted for dispatching a plurality of elevator cars in sequence from a dispatch landing located in the lowermost portion of a building, said cars being operated in their respective hoistways by said elevator control to serve a plurality of floor landings located in a predetermined upper portion of said building while bypassing all oor landings located below said predetermined upper portion except said dispatch landing, a device for providing advance dispatch information, said device comprising, first car position determining means responsive to said elevator control for determining the position of said cars relative to each other while said cars are below said upper y portion and are traveling landing, second car position determining means also responsive to said elevators control for determining the presence of any of said cars at said dispatch landing, advance availability means responsive to said first determining means for selecting the lowermost car traveling downward as being available tor dispatching in advance of its arrival at said dispatch landing provided that car is below said predetermined upper portion of the building and traveling at normal speed, availability means re'- sponsive to both said advance availability means and said second car position determining means for selecting as available for dispatching said car so determined by said second car position determining means as being present at said dispatch landing and in the absence of such a determination selecting as available for dispatching said lowermost car selected by said advance availability means as being available for dispatching in advance of its arrival at said dispatch landing, selecting means responsive to operation of said availability means for selecting as next to be dispatched said car so selected as available for dispatching by said availability means and for maintaining such selection preventing any further selection of said cars as next to be dispatched until said car so selected as next is dispatched by said elevator control, rst means responsive to said selecting means once any of said cars has been selected as next for causing said availability means to select as the second carto be dispatched a car determined by said second car position determining means as being present at said dispatch landing and in the absence of such a car causing said advance availability means to select in advance of its arrival at said dispatch landing the next lowermost of said down- Ward traveling cars as the second car to be dispatched, second means responsive to operation of said first means for preventing operation of both said availability means and said advance availability means for preventing selection of a car as being available for dispatching, and indicating means for each car positioned above the entranceway of each car at said dispatch landing, said indicating means being responsive to operation of said selecting means and said availability means for indicating the selection of said cars as the next and second cars to be dispatched, thereby informing waiting passengers at the dispatch landing which will be the next car dispatched and which car will be the second car dispatched even though said cars may not be presently positioned at said dispatch landing.

19. In combination with an elevator control system adapted for dispatching a plurality of elevator cars in sequence from a dispatch landing located in the lowermost portion of a building, said cars being operated in their respective hoistways by said elevator control to serve a plurality of door landings located in a predetermined upper portion of said building while bypassing all oor landings located below said predetermined upper portion except lsaid dispatch landing and a basement' landing located below said dispatch landing, a device for providing advance dispatch information, said device comprising,` rst car positionl determining means responsive to said elevator control for determining the position of said cars relative to each other while said cars are below said upper portion and traveling toward said landing at normal speed, second car position determining means also responsive to said elevator control for determining the presence of any of said cars at said dispatch landing, advance availability means responsive to said rst determining means for selecting the lowermost car traveling downward as being available for dispatching in advance of its arrivalat said dispatch landing, provided that car is below said predetermined portion of the building,

i availability means responsive to both said advance availability means and said second car position determining means for selecting as available for dispatching said car at normal speed toward saif so determined by said second car position determining means as being present at said dispatch landing and in the absence of such a determination, selecting as available for dispatching in advance of its arrival at the dispatch landing said lowermost car selected by said advance availability means as being available for dispatching, selecting means responsive to operation of said availability means for selecting as the next car to be dispatched said car so selected as available for dispatching by said availability means and for maintaining such selection, preventing any further selection of a next car until said car so selected as next is dispatched by said elevator control, rst means responsive to said selecting means once any of said cars has been selected as next for causing said availability means to select as the second car to be dispatched a car determined by said second car position determining means as being present at said dispatch landing and in the absence of such a car causing said advance availability means to select in advance of its arrival at said dispatch landing the next lowermost of said downward traveling cars as the second car to be dispatched, third car position determining means also responsive to said elevator control for determining the presence of any of said cars below said dispatch landing, second means responsive to operation of said third car position determining means and to operation of said iirst means responsive to said selecting means for preventing operation of both said availability means and said advance availability means for preventing selection in advance of its arrival at said dispatch landing ot a car being available for dispatching, basement call registering means for each car responsive to a call for service for said basement landing for that car provided that car is not already selected as said next car by said selecting means and is not already selected as said second car availability means, said basement call registering means when so responsive preventing operation of both said advance availability means and said availability means from selecting that car, and indicating means for each car positioned above the entranceway of each car at said disptach landing, said indicating means being responsive to operation of said selecting means and said availability means for indicating the selection of one of said cars as the next car to be dispatched and the selection of another of said cars as the second car to be dispatched, thereby informing waiting passengers at the dispatch landing which will be the next car dispatched and which car will be the second car dispatched even though said cars may not be presently positioned at said dispatch landing.

20. An advance dispatch information device as claimed in claim 19 wherein the iirst car position determining means comprises a unidirectional power source, a plurality of resistor-capacitor networks, one for each of said cars, and a plurality of switching means, one each of which is provided for each of said cars and is adapted to be actuated from a first condition to a second condition as its associated car while traveling downward at normal speed arrives at a point located a predetermined distance below said upper portion of said building and is actuated from said second condition back to said rst condition as said car arrives at said point while traveling upward, each of said switching means when so actuated to said second condition being effective for electrically connecting its associated one of said resistor-capacitor networks across said power source for charging the condenser of the network so connected and when so .actuated back to said first condition disconnecting said network from said power source, each of said condensers having a predetermined value of capacity sufficient to insure that it will not approximate its fully charged condition until after its associated down traveling car arrives at said dispatch landing.

No references cited 

